chore(deps): update actions/checkout action to v6

| datasource  | package          | from | to |
| ----------- | ---------------- | ---- | -- |
| github-tags | actions/checkout | v5   | v6 |


Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/barman-base-image.yml

@@ -19,7 +19,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install QEMU static binaries
         uses: docker/setup-qemu-action@v3
       - name: Install Task

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
           df -h
           echo "-----------------------------------------------------"
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         # We need the full history for the commitlint task
         with:
           fetch-depth: 0

.github/workflows/publish-docs.yml

@@ -25,7 +25,7 @@ jobs:
       contents: read
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Node
         uses: actions/setup-node@v6

.github/workflows/release-please.yml

@@ -19,7 +19,7 @@ jobs:
       #   We'll use the cli until there's a fix for
       #   https://github.com/googleapis/release-please/issues/2280.
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install node
         uses: actions/setup-node@v6
         with:

.github/workflows/release-publish.yml

@@ -13,7 +13,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install QEMU static binaries
         uses: docker/setup-qemu-action@v3
       - name: Install Task